Many endoscopes have a viewing angle parallel to the longitudinal axis of their shaft. Increasingly, however, endoscopes with a different fixed viewing angle or with an adjustable viewing angle are demanded and are being developed. In addition, endoscopes with adjustable field of view or adjustable focal length and additional functions are in demand and are being developed. To include new fields of application, the shaft diameter is constantly being reduced. In the process, however, the need to provide the structural space necessary for devices of the observation beam path, of the illumination beam path, for adjusting the viewing angle, the field of view or other functions, constitutes a considerable challenge.